1. Field of the Invention
The present invention relates to a user interface including a display device and a touch panel disposed on a screen of the display device.
2. Description of the Related Art
As a technique related to a user interface using a touch panel disposed on a screen of a display device, the following technique has been known. That is, a vibrator for vibrating a touch panel is provided, a user's operation of touching an area of the touch panel corresponding to a button displayed on a display device is accepted as a button touching operation, and a response to the touch operation is fed back to the user by using vibration of the touch panel (e.g., Patent Documents 1 and 2: Japanese Unexamined Patent Application Publication Nos. 2003-16502 and 2000-137576).
Also, as another technique related to a user interface using a touch panel disposed on a screen of a display device, the following technique has been known. That is, after a user has touched a touch panel, a button displayed in an area of a display device corresponding to the touched position just before a release operation (user's operation of releasing his/her finger from the touch panel) is accepted as a button decided by the user (e.g., Patent Documents 1 and 3: Japanese Unexamined Patent Application Publication Nos. 2003-16502 and 9-62446).
Furthermore, in these techniques, when the user performs touch and release operations on the touch panel, if the touched position just before the release operation is different from the position of the button corresponding to the touched position at the touch operation, selection of the released button is not accepted (e.g., Patent Document 3).
The sensitivity characteristic of a touch panel varies from one product to another. More specifically, the forces to be exerted on a touch panel and the touch angle required for allowing the touch panel to detect a touch vary from one touch panel to another.
For this reason, even when a user touches a proper operating position on a touch panel, the touch panel may not be able to detect the touch and accept the operation according to the user's intention, depending on the user's operation or user's status.